Steam superheater



G. C. VENNUM ET AL s'yrEAu SUPERHEATER filed Feb 16. 1922 s sheets-sneer g Patented Sept. 1, 1925.

A i v1,552,112@ UNITED sTATEs4 PATENTU OFFICE.

GEORGE c. vENNUM, 0E WESTEIELD, NEW JERSEY, AND EENRYB. BRADFORD, OE EDGE MOOR, EEANDYWINE HUNDRED, DELAWARE, AssrGNOEs To EDGE MOOR IEON COMPANY, OE EDGE MOOR, DELAWARE, A coEroRArroN OF DELAWARE.

STEAM SUPERHEATEE .application filed February 16, 1922. Serial No.. 536,901.

To all whom it' may concern Beit known that we, GEORGE C. VENNUM, a citizen of the United States ot' America, and residentof 'VVestlielth county oit Union, State of N ew Jersey, and HENRY B.A BRAD`V FORD, a citizen of the United States of Amer# ica, and resident of Edge Moor, Brandywine Hundred, county of New Castle, State of Delaware, have invented certain vnew and useful Improvements in Steam Superheaters, of which thefollowing is a true and exact description, reference being had to the accompanying drawings, which form a part thereof. Y l

Uur invention relates to steam superheaters and has for its object to provide a superheater which in its construction and in the way in which it is secured inl place in the boiler is especially well adapted both to per-` form its function of superheating steamk and also to withstand with'out'injury the inter`v nal strains to which it is subjected by vary-v ing temperatures. A further andparticuf larly important object of our invention is to provide a superheater especially well adapted to operate in such a way lthat the steam super-heated in it can be delivered at a pr-ac`` tically constant temperature. y

' Thenature of our. improvements will :be best understood as Adescribedin connection with the drawings' which they are `illustrated in yconnection with a boiler invented by George C. Vennuin and for which he has led an application yfor Letters Patent bearing the Serial No. 482,086, for the reason that ourimproved superheater is especially lwell adapted for use in connection with the Vennum boiler.

In the drawings: Y Fi urel is a sectional side elevation of the perheater shown in position therein.

Figure 2 is a plan view of the boiler and superheater shown Vin Fig. l with the boiler casing removed and the upper front drum shown partly in section, the other rear drum and its connections partly cut away and with the roof of the lire boxpartly removed. Figure 3 is a crosssectional view talrenas on the line 3 3 of Fig. l, showing the rsuperheater in front elevation.

Figure l isaplan view of the superheater together with a diagraminaticv showing of the Veleetre-mechanical mechanism provided ennum boiler with our improved su- 'lor automatically operating .the dampers o'l vthe superheater, and

Figure 5 is an end elevation of the .super.

. heater with its connections as'shown in Figs.

3 and el. and withthe headersto which the superheated tubes are connected shown in section,

A is the lire box of the boiler opening into a large combustion chamber indicated at A which in turn connects with chamber A2 through the `tube-s of the boiler. B is" the bottom drum of the boiler ;4 B rand B2 he upper drums. rEhe drums B and.v B are connected by a tube `bankfindicated .at C."

The. upper drums B 'and B2 are connected.:

through the pipes indicated at Cf andv the drums B2and are vconnected by "circu-' lation tubes indicated at @2.5 D is the rear chamber of the boiler enclosed between converging walls indicated at D7 D', and vopening to the stack or take-oit' tluesth-rough the passage .indicated at D2. E, E2, and Etindicate three groups of headers' connected together .by tubes'as indicated' at F 'and located 'at the'to'p otA the chamber D, vthese headers being connected with the VVgrol'ipsofheaders E3, E and-Elocatedat the bot.v toni o1- the chamber D through tube .groups indicated at F, F2 and F3.' Grindicates the pipe and valve .system by V`which Water is fed tothe ,headers indicated at E, E2. and E4. 121, 11, etc. ,are tubes connecting the header lgroup'l1t with'th'e druniB2.V 1 are steam take-ott pipes .connected with Vthe header. groupfE* and openinginto a head` f er I which communicateswith the steam J `indicates our improved. superheater num boiler which forms in itself'n'o kpart ofA space of the drum B2 through pipes indi kf cated at I2.

made up, as shown, of a header J which isv f connected to the steam space ofthe drum B2 through pipes indicated atM. The header J isconnected to Athe 'bottoni header 'in- 'dicated atJ2 by groups of tubes indicatedk at KV so disposed as to leave openings'ni# dicated at L, L, between the groupso'ftubes.

The header J 2 is connected to -a' header J2.

by short tubes, asshown, these two headers `forming practically one header Mand 'the lthird bottom header J3 isrin turn-connected are interposed springs indicated at N2, N2,

which tend to draw the supporting part of the stirrup upward so that the stirrups will continue to perform their supporting function even if the tube groups K should be v place.

elongated by heating to a greater extent than the tube groups K.

0,0, are dampers secured to rotatable shaft-s indicated at O', O2, which move in lbearings O3, O2, secured to the headers, as

shown in Fig. 3, the dampers being so placed and proportioned as to close thev open passages L in one position and to leave these passages practically open when turned through an angle of 902. The upper rotatable shafts O are, as shown, supported by chains indicated at P and a chain or other easily twistable support is highly desirable as a means of supporting the dampersV in To the bottoms of the lower shafts O2 are secured crank arms indicated at Q, Q, which are in turn secured to a damper actuating rod indicated at R and having, as indicate at R a limit stop secured to its outer end. S, see Fig. 4, is a worm wheel tol which is secured a crank arm- S connected to the damper rod Rf: The worm wheel S is actuated through a worm T securedon the shaft T to which is also securedpthe large gear wheel T2 engaged by the small gear T? of the shaftV Ttl of a reversing electric motor indicated at T5, T6 indicating an electric brake on the shaft T4.

X is a thermostat located, as shown, at the outlet of the header J 5 and connected to actuate a two point switch indicated at V.l

limit switch U and when this switch is closed through the wire VV to the other n wiring' of the motor. The current through either motor winding passes through the wire W5 through the electric break indicated at T'6 and thence through the wiring indicated at W6.

In operation the superheater constructed as described is located immediately in the rear of the headers B, B2, and directly across and so as to entirely -fill the space for the boiler gases by which. the gases froml the chamber A2 pass to the chamber D and it will be observed that when the dampers O are closed as indicated in Figs. 3 and 4, all of the gases pass through the tube groups of the superheater which are preferably staggered,`as indicated in F ig. 4, and which in this position of the dampers receive the maximum amount of heat from the boiler gases and secure, of course the maximum superheating of the steam. Again, it will be obvious that when the dampers O are partly or wholly open a large portion of the gas from the chamber A2 will pass 'to the chamber D of the boiler without passing through the tubes of the superheating groups but whateverincreased heat of the boiler gases is thus` passed through the superheater without utilization is fully utilized by the boiler tubes in the'chamber D .1t is, of course., advisable that the position of the dampers in the superheater should be controlled and regulated by the temperature of the steam as it issues from the superheater. This couldr be accomplished in many ways and, as shown, we effect this control by means of a thermostat indicated at X which connects the circuit wire TV either with the circuit wire W or the circuit wire W3 as thetemperature of the superheated steam rises or falls between certain points and thus energizes the motor alternately in opposite directions. The rotation of the motor through the gears indicated and described communicates a slow and gradual motion to the wormV wheel S and through the crank arm S to the damper rod R and to the dampers. The `limit stop R on the damper rod opens one or the other of the limit switches Il or-U in the position of the rod in which the damper is fully closed or fully opened, thus cutting off the current to the motor. To insure that the motion of the dampers shall be promptlyarrested when the motor circuits are opened as above described we prefer to employ an electrically operated stop such as a brake. `This can be located in any convenient place and, as shown, we provide abrake T acting on a brake drum onl the motor shaft which so long as a cir-A cuit 1s passing through the motor is nonoperative but which acts to arrest the motion of the shaft and `connected parts as soon as current lceases to yllow through the motor. l Y

By sustaining the superheater in position and sustaining also the dampers-O, O, in a vertical position the distortion of the su- Vperheater and dampers from the effect of changing temperatures is minimized and by constructing the superheater with its upper header secured in position and its lower header or headers :tree to move, distortion and strains due to temperature variation are minimized while, as we have pointed out, the use of springs in the hangers ot the headers J also compensates for the eiiect of varying temperature and maintains proper support for the header J even although its tubes be disproportionately longer with reference to the tube groups K1.

Having now described our invention, what we claim as new and desire Letters Patent, is:

1.In combination with a steam boiler having a contracting gas pass through which t-he heating gases pass, a wide and comparatively shallow superheater made up of substantially straight tubes connected at their ends to headers, said superheater being located in and extending substantially across the full width and height of said gas pass, and having its tubes arranged in groups with an open space or spaces' between said groups, and one or more dampers located in said open spaces, whereby said spaces can be regulated in area.

2. In combination with a steam boiler having a horizontal contracting gas pass through which the heating gases pass, a vertically extending wideand comparatively shallow superhea-ter located in and eX- tending substantially across the full width and height of said gas pass and having its tubes arranged in vertical groups with an to secure by' open vertical space or spaces bet-Ween said groups and vertical damper-s located in said open spaces.

3. A wide and comparatively shallow suf perheater made up of groups of substantially parallel vertical tubes with free vertical spaces between said groups; the tubes being held in remotely placed headers in which the headers at the top of -thetubes are adapted to be connected to the steam inlet and outlet .connections and the bottom headers are free to move, vin combination with vertical dampers located in said free spaces whereby they can be closed or regulated for the passage of gases.

4. In combination with a steam boiler having a horizontal gas pass through which Vvthe heating gases pass, a vertically extend* ingsuperheater located in and substantially filling said gas pass and having its tubes arranged in groups with an open space or spaces between said groups and dampers located in said open spaces and suspended in place thereinby freely twistable supports.v f

5. A superheater made up of substantial' ly parallel tubes connected at 'their tops to 7 separate inlet and outlet headers and at` bottom to a common header free to move with a reference to the top headers in combination with y means for supporting the inlet header and) resilient nneans for independently supporting the outlet header.

GEORGE c. vinirnnu.` HENRY B. BRADFORD. 

